CFD Online Discussion Forums - LISA atomization model in sprayFoam

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- OpenFOAM Pre-Processing (https://www.cfd-online.com/Forums/openfoam-pre-processing/)

- - LISA atomization model in sprayFoam (https://www.cfd-online.com/Forums/openfoam-pre-processing/135689-lisa-atomization-model-sprayfoam.html)

LISA atomization model in sprayFoam

Dear all,

I am trying to model spray combustion with sprayFoam. In my case, the liquid fule is injected by a pressure-swirl atomizer. I want to use LISA model to simulate the atomization process. But I have no idea on how to set up this model, I am really new with OpenFOAM:(. Could anyone please give me some instructions or share a setting file, e.g. 'sprayCloudProperties', where LISA model is used?

Thanks a lot in advance!

Best,
Likun

Hey Likun,

did you find your answer yet?

I have been trying to set up the AachenBomb tutorial without combustion and I set LISA as atomizationModel and added LisaCoeffs to the sprayCloudProperties:

Code:

    LISACoeffs

    {

        Cl                              0.5;

        cTau                            12.0;

        Q                               1.0e-3;

        J                               0;  // not used

        lisaExp                         0.27;

        injectorDirection               (0 -1 0);

        SMDCalculationMethod            method2;

    }

I was just following all the error messages and added the parameters OF wanted me too. The first 4 were discussed in this thread:

http://www.cfd-online.com/Forums/ope...ray-model.html

I don't know what lisaExp is, just found the value 0.27 somewhere in this forum. InjectorDirection should be the same as in "sprayCloudProperties" -> "injectionModels" -> "direction". For SMDCalculationMethod there are 2 files located in

./src/lagrangian/spray/submodels/AtomizationModel/LISAAtomization

You can choose between method1 or method2. If you write i.e. banana as value, OF will automatically use method2, because of the following lines in LISAAtomization.C

Code:

    SMDCalcMethod_(this->coeffDict().lookup("SMDCalculationMethod"))

{

    // Note: Would be good if this could be picked up from the injector

    injectorDirection_ /= mag(injectorDirection_);



    if (SMDCalcMethod_ == "method1")

    {

        SMDMethod_ = method1;

    }

    else if (SMDCalcMethod_ == "method2")

    {

        SMDMethod_ = method2;

    }

    else

    {

        SMDMethod_ = method2;

        Info<< "Warning: SMDCalculationMethod " << SMDCalcMethod_

            << " unknown. Options are (method1 | method2). Using method2"

            << endl;

    }

}

I hope that could help a bit, it seems we are both on a similar way (trying to simulate sprays) at the moment. I have read your name in various other threads that I was searching for information in.

Best regards, Sebastian

Dear Sebastian,

Thanks a lot for the informative answer. I have already tried the settings as you suggested, it indeed works, but I have not validate the results with experimental data yet. Because I don't understand what those parameters stands for, like 'lisaExp'. And also wondering why the injection pressure in not a input parameter as the case for the LISA model in Fluent.

Besides the spray model, I am now more struggling with the combustion model. I want to simulate a spray flame, and want to use the FGM model implemented by Hannes Kroger:

http://www.cfd-online.com/Forums/ope...ion-model.html

But I have a lot of troubles in compiling these code into OpenFOAM-2.3.0. As I understand there are a lot of differences between OF 1.x.x (where this code was originally compiled with) with OF 2.x.x. If you also work on combustion, e.g. thermophysicalModels, maybe we can share some information on this.

Best regards,
Likun

Hey Likun,

I didn't validate my calculations either, as I haven't got any usefull experimental data yet. But thats future work for me, as I am still trying to get the sprayFoam simulation up properly.

Unfortunately I am not using combustion at the moment. My aim for the moment is achieving sensible size distributions via atomization and breakup models.

Sorry, that I can't help you with that by now.

Hi Sebastian,

Please keep me posted when you have progress on spray simulation, I will let you know the progress on my side.

Likun

Hello Likun,

I am trying to understand LISA code.

I have studied Senecal and Schmidt paper but I am unable to understand this two particular lines of the code.

1) k=kPos-(derivPos/((derivNeg-derivPos)/(kNeg_KPos)))
From where this equation comes for finding wave number??

2) what is derivPos??

Thanks in advance

Hello vishal,

Now I am only working with gas phase combustion model. I will come to spray part soon, but sorry at this moment I can not help you.

Best,
Likun

Dear all,

Do you find meaning of LISA parameters especially lisaExp,? what is this?

and other question, when spray starts in sprayFoam simulaton, many particles or droplets injected to air ,e.g. . so why do we use from LISA, because LISA is responsible for changing ligament to droplet and here droplets exist in start of simulation?